Plastic Bag Fight
Pits U.S. Makers
V. U.S. Importers

When fierce overseas competition forced a Sonoco Products Co. plastic bag-making business to close its Santa Maria, Calif., plant last year, ending 100 jobs, the company went on the offensive.

Sonoco and four other U.S. makers of plastic shopping bags, used by grocery and department stories, charged that manufacturers in China, Thailand and Malaysia were violating U.S. antidumping laws by selling the bags in the U.S. below cost. In a petition to the International Trade Commission, the U.S. manufacturers, calling themselves...